6 Tests and Error Messages

Order in Which POST Tests Are Performed

Checkpoint

POST Routine Description (Continued)

Code

(A Check Point Code is NOT an error code or error number)

 

 

30h

Display memory read/write test passed. Looking for retrace checking.

 

 

31h

Display memory read/write test or retrace failed. Performing the alternate display retrace

 

checking.

 

 

32h

Alternate display memory read/write test passed. Looking for alternate display retrace

 

checking.

 

 

34h

Video display checking is complete. Setting the display mode.

 

 

37h

Display mode is set. Displaying the display mode text.

 

 

38h

Initializing the bus input, IPL, and if present and general devices.

 

 

39h

Displaying the bus initialization errors.

 

 

3Ah

New cursor position has been read and saved. Displaying the Hit <DEL> message.

 

 

40h

Preparing the descriptor tables.

 

 

42h

Descriptor tables are prepared. Entering protected mode for the memory test.

 

 

44h

Interrupts enabled if the diagnostics switch is on. Initializing data to check memory wrap-

 

around at 0:0.

 

 

45h

Data initialized. Checking for memory wrap-around at 0:0 and finding total system memory

 

size.

 

 

47h

Memory pattern has been written to extended memory. Writing patterns to the base

 

640 KB memory

 

 

48h

Patterns written in base memory. Determining the amount of memory below 1 MB.

 

 

49h

Amount of memory below 1 MB has been found and verified. Determining the amount of

 

memory above 1 MB.

 

 

4Bh

Amount of memory above 1 MB has been found and verified. Checking for a soft reset and

 

clearing the memory below 1 MB for the soft reset. If this is a power on situation, going to

 

checkpoint 4Eh.

 

 

4Ch

Memory below 1 MB has been cleared via a soft reset. Clearing the memory above 1 MB.

 

 

4Dh

Memory above 1 MB has been cleared via a soft reset. Saving the memory size. Going to

 

checkpoint 52h.

 

 

4Eh

Memory test started, but not as the result of the soft reset. Displaying the first 64 KB

 

memory size.

 

 

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